Remove some InterfacePtr<> methods which directly deal with message pipe handles.

mojo/gpu/gl_context.cc

Index: mojo/gpu/gl_context.cc
diff --git a/mojo/gpu/gl_context.cc b/mojo/gpu/gl_context.cc
index d34b3a54cee4fce108342284191225e4e187408c..73941d64488c8393f1f8f54f7cefd293fbcf1766 100644
--- a/mojo/gpu/gl_context.cc
+++ b/mojo/gpu/gl_context.cc
@@ -22,8 +22,8 @@ GLContext::GLContext(Shell* shell) : weak_factory_(this) {
   CommandBufferPtr command_buffer;
   gpu_service->CreateOffscreenGLES2Context(GetProxy(&command_buffer));
   context_ = MojoGLES2CreateContext(
-      command_buffer.PassMessagePipe().release().value(), &ContextLostThunk,
-      this, Environment::GetDefaultAsyncWaiter());
+      command_buffer.PassInterface().PassHandle().release().value(),
+      &ContextLostThunk, this, Environment::GetDefaultAsyncWaiter());
   gl_ = static_cast<gpu::gles2::GLES2Interface*>(
       MojoGLES2GetGLES2Interface(context_));
 }